Liquid treatment system and liquid treatment method

ABSTRACT

Liquid treatment units are disposed in multi-tiers surrounding a main-arm  35.  Among liquid treatment units, plating units M 1  through M 4  are disposed on a lower tier side, and a unit for post-treatment process such as a cleaning unit  70  where a cleaner atmosphere is necessary is disposed on an upper tier side. Thereby, an improvement in an area efficiency and the formation and maintenance of a clean atmosphere can be simultaneously obtained.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to liquid treatment of a substratesuch as a semiconductor wafer or the like, in particular to a liquidtreatment system using a plurality of liquid treatment units and aliquid treatment method therefor.

[0003] 2. Description of the Related Art

[0004] When forming a metal layer on a surface of a substrate such as asemiconductor wafer or the like, a liquid treatment method such asplating method or the like is employed.

[0005] When forming a metal layer by means of a plating method, aplating solution bath accommodating a plating solution is necessary.

[0006] With the increase of structural complexity in a semiconductorelement, a semiconductor wafer has been frequently plated with aplurality of plating solutions of different compositions, resulting inan increase of the number of plating solution baths being used.

[0007] Furthermore, in order to treat a large number of semiconductorwafers at a time to reduce a manufacturing cost, the number of platingsolution baths being disposed in a treatment chamber increases.

[0008] However, when many plating solution baths are disposed, anincrease of an occupation area of equipment deteriorates utility andefficiency of the site.

[0009] Furthermore, mist containing the plating solution diffuses fromthe plating solution bath to contaminate the inside of the treatmentchamber, thereby causing a possibility of deteriorating quality of themetal layer.

[0010] Still furthermore, when adjacently disposing the plating solutionbaths of different compositions, the plating solution is likely to enterfrom one plating solution bath into another one.

SUMMARY OF THE INVENTION

[0011] An object of the present invention is to provide a liquidtreatment system high in utility and efficiency of a lot area.

[0012] Another object of the present invention is to provide a liquidtreatment system capable of separately controlling an atmosphere of theliquid treatment system or each liquid treatment unit, and a liquidtreatment method therefor.

[0013] Still another object of the present invention is to provide aliquid treatment system capable of densely disposing the liquidtreatment units that use different kinds of treatment solutions.

[0014] (1) A liquid treatment system involving the present inventioncomprises

[0015] a first liquid treatment unit for implementing a first liquidtreatment with a first treatment solution containing a metal ion on asubstrate,

[0016] a second liquid treatment unit for implementing a second liquidtreatment on the substrate thereon the first liquid treatment isimplemented, and

[0017] a first transfer unit for transferring the substrate in avertical direction,

[0018] wherein the first and second liquid treatment units are disposedin multi-tiers in a vertical direction surrounding the first transferunit.

[0019] Due to the multi-tier disposition of the first and second liquidtreatment units, an occupation area of the liquid treatment system canbe suppressed smaller.

[0020] The first liquid treatment unit may implement the first liquidtreatment on a first surface of the substrate and the second liquidtreatment unit may implement the second liquid treatment on a secondsurface of the substrate. In addition to the above, the first transferunit may have a function of turning upside down surfaces of thesubstrate.

[0021] The first and second liquid treatment units can treat bothsurfaces of the substrate, respectively. Accordingly, treatmentefficiency can be improved. Furthermore, when the first transfer unithas the function of turning upside down the substrate, the reversalmechanism is not necessary to be separately disposed, and furthermorethe reversal of the substrate being facilitated during the transfer.

[0022] The liquid treatment system may further comprise a first gas feedmeans for feeding a cleansed gas in the liquid treatment system,

[0023] wherein the second liquid treatment unit may be disposed on anupstream side of the flow of cleansed gas than the first liquidtreatment unit.

[0024] The second liquid treatment unit is disposed on an upstream sideof the flow of cleansed gas than the first liquid treatment unit.Accordingly, an atmosphere on the second liquid treatment side can bemaintained clean.

[0025] The liquid treatment system may further comprise a secondtransfer unit for transferring the substrate out of the second liquidtreatment unit.

[0026] The substrate treated by the second liquid treatment unit is, bymeans of the second transfer unit, transferred outside the second liquidtreatment unit. Accordingly, the first transfer unit is prevented fromtouching the substrate treated by the second liquid treatment unit tocontaminate.

[0027] The second liquid treatment unit may be disposed above the firstliquid treatment unit.

[0028] For instance, a cleaning unit as the second liquid treatment unitis disposed above a plating unit as the first liquid treatment unit. Asa result, the second liquid treatment unit is contaminated with moredifficulty by an atmosphere of the first liquid treatment unit.

[0029] The liquid treatment system may further comprise a heating unitfor heating the substrate thereon the first liquid treatment is applied.

[0030] By means of the heating unit, heating such as annealing forreforming a copper plating layer formed on the substrate can beimplemented.

[0031] The liquid treatment system may further comprise a temperaturecontrol means for controlling a temperature in the liquid treatmentsystem.

[0032] By suppressing a temperature rise in the liquid treatment system,mist from the treatment solution can be less generated.

[0033] The first and second liquid treatment units are units independentfrom each other and detachable respectively from the liquid treatmentsystem.

[0034] Since the first and second liquid treatment units are detachablefrom the liquid treatment system respectively, maintenance is easy andmaintenance efficiency can be improved. Furthermore, since the first andsecond liquid treatment units are independent from each other, whentroubled, it can be easily replaced.

[0035] The first liquid treatment unit may have a housing capable ofmaintaining an interior atmosphere thereof approximately airtight.

[0036] Thereby, the mist of the treatment solution is prevented fromflowing out of the first liquid treatment unit to contaminate anexterior atmosphere of the first liquid treatment unit.

[0037] The first liquid treatment unit may further comprise a second gasfeed means for feeding a cleansed gas in the housing.

[0038] By the use of the second gas feed means, a clean atmosphere canbe maintained in an interior of the first liquid treatment unit.

[0039] The first liquid treatment unit may further comprise an exhaustmeans for lowering a pressure of the housing interior than that of thehousing exterior.

[0040] When sending the substrate in and out of the housing,contaminated air can be prevented from flowing outside the liquidtreatment unit.

[0041] The first liquid treatment unit may further comprise atemperature control means for controlling a temperature in the housing.

[0042] By suppressing a temperature rise in the liquid treatment unit,the mist can be less generated from the treatment solution.

[0043] The interior of the housing may be partitioned in two of a firsttreatment portion including a transfer position for transferring in andout the substrate, and a second treatment portion including a liquidtreatment position for implementing the first liquid treatment on thesubstrate.

[0044] In the second treatment portion, the first liquid treatment thatis likely to generate the mist of the treatment solution is carried out.Furthermore, in the first treatment portion, the substrate is sent inand out. That is preferable to be implemented in a cleaner atmosphere.Thus, by partitioning the interior of the housing according tocleanliness, when sending the substrate in and out of the firsttreatment portion, the mist of the treatment solution can be preventedfrom flowing out.

[0045] The first and second treatment portions may include a cleaningposition for cleaning the substrate and a spin dry position for spinningthe substrate to throw off a first cleaning fluid, respectively.

[0046] (2) A liquid treatment method involving the present inventioncomprises

[0047] a first liquid treatment step for implementing a first liquidtreatment on a substrate by means of a first liquid treatment unitaccommodating a first treatment solution containing a metal ion,

[0048] a cleaning step for water cleaning in the first liquid treatmentunit the substrate thereon the first liquid treatment is implemented inthe first liquid treatment step,

[0049] a transfer step for transferring the substrate cleansed in thecleaning step, together with adsorbed moisture, by means of a transferunit, to a second liquid treatment unit, and

[0050] a second liquid treatment step for implementing a second liquidtreatment, by means of the second liquid treatment unit, on thesubstrate transferred in the transfer step.

[0051] A component of the first treatment solution on the substratedries during the transfer to prevent particles from forming on thesubstrate.

[0052] (3) A liquid treatment method involving the present inventioncomprises

[0053] a first liquid treatment step for implementing a first liquidtreatment on a first surface of a substrate by means of a first liquidtreatment unit accommodating a first treatment solution containing ametal ion,

[0054] a reversal step for turning, during transfer to a second liquidtreatment equipment by means of a transfer unit, upside down front andback surfaces of the substrate on which first surface the first liquidtreatment is implemented in the first liquid treatment step, and

[0055] a second liquid treatment step for implementing, by means of thesecond liquid treatment unit, a second liquid treatment on a secondsurface of the substrate of which front and back surfaces are turnedupside down in the reversal step.

[0056] The substrate is turned upside down during the transfer from thefirst liquid treatment unit to the second liquid treatment unit.Accordingly, the first and second liquid treatment can be efficientlyimplemented on the first and second surfaces of the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0057]FIGS. 1 through 4 each are perspective, plan, front and side viewsof a plating system involving the present invention.

[0058]FIG. 5 is a vertical section of a plating unit involving thepresent invention.

[0059]FIGS. 6 and 7 are vertical sections of a cleaning unit involvingthe present invention.

[0060]FIGS. 8 and 9 each are plan and vertical sectional views of anannealing unit involving the present invention.

[0061]FIG. 10 is a flow chart showing a process flow of an entireplating system involving the present invention.

[0062]FIG. 11 is a flow chart showing a flow of plating processimplemented in a plating unit.

[0063]FIGS. 12 through 23 are diagrams showing schematically therespective steps of plating.

[0064]FIG. 24 is a flow chart showing a flow of cleaning implemented ina cleaning unit.

[0065]FIG. 25 is a flow chart showing a process flow in a manufacturingmethod of a semiconductor device involving the third embodiment of thepresent invention.

[0066]FIG. 26A through 26D are vertical sections showing a semiconductordevice in a manufacturing method of a semiconductor device involving thethird embodiment of the present invention.

[0067]FIG. 27 is a flow chart showing a process flow in a manufacturingmethod of a semiconductor device involving the fourth embodiment of thepresent invention.

[0068]FIGS. 28A through 28D are vertical sections showing asemiconductor device in a manufacturing method of a semiconductor deviceinvolving the fourth embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

[0069]FIGS. 1 through 4 each are a perspective view, a plan view, afront view and a side view of a plating system 1 involving a firstembodiment of the present invention. In the following, with reference toFIGS. 1 through 4, the plating system 1 involving the present embodimentwill be explained.

[0070] The plating system 1 is constituted of a carrier station 2sending in and out and transferring a semiconductor wafer W (hereafter,refers to as wafer W), and a process station 3 implementing actualtreatment on the wafer W.

[0071] The carrier station 2 is constituted of a susceptor 21 fordisposing the wafer W and a sub-arm 22 as a second transfer means fortransferring the wafer W.

[0072] On the susceptor 21, in an X direction in the drawing, forinstance four carrier cassettes C are disposed. In each carriercassette, a plurality, for instance 25 sheets, of wafers W areaccommodated level equidistance apart in a vertical direction.

[0073] The sub-arm 22 is capable of, in addition to moving on a raildisposed in an X direction in the drawing, elevating in a verticaldirection (Z direction) and spinning in a level plane. The sub-arm 22makes access to the interior of the carrier cassette C disposed on thesusceptor 21 to take out an untreated wafer W and accommodate a treatedwafer W in the carrier cassette C. Furthermore, the sub-arm 22 deliversthe wafer before and after the treatment between the process station 3.

[0074] The process station 3 has an appearance of a cubic orparallelepiped box, an entire surroundings thereof being covered by ahousing 31 made of corrosion resistant material, such as for instanceresin or a metal plate of which surface is coated by resin.

[0075] Inside the process station 3, a treatment space S that is atreatment chamber is formed in an approximately cubic or parallelepipedbox.

[0076] To a bottom of the treatment space S, a base plate 33 isattached. As shown in FIGS. 1 and 2, in an approximate center of thebase plate 33, a main-arm 35 is disposed as a first transfer means fortransferring the wafer W. Furthermore, in the surroundings of themain-arm 35 on the base plate 33, four sets of plating units M1 throughM4 are disposed.

[0077] The main-arm 35 is capable of elevating in a Z direction andspinning in a level plane, and provided with two upper and lower waferholders 35 a capable of extending in an approximate level plane. Themain-arm 35, by extending these wafer holders 35 a, can deliver thewafer W before and after the treatment in the treatment unit disposed inthe surroundings of the main-arm 35. Furthermore, the main-arm 35 canmove in a vertical direction to make access to an upper side treatmentunit. Accordingly, the main-arm 35 can transfer the wafer W from atreatment unit on a lower tier side to that on an upper tier side, or onthe contrary from the treatment unit on the upper tier side to that onthe lower tier side.

[0078] Furthermore, the main-arm 35, being provided with a function ofturning upside down a held wafer W, can turn upside down the wafer Wduring the transfer of the wafer W between the treatment units. Thefunction of turning upside down the wafer W is not an indispensablefunction of the main-arm 35.

[0079] Above treatment unit, on a closer side to the carrier station(that is, above the plating units M1 and M2), for instance two of othertreatment units are disposed. To the other treatment unit, for instancea cleaning unit 70 as a second treatment unit corresponds.

[0080] Since a plurality of treatment units are disposed in multi-tiersin an up and down direction, the utility and efficiency of an area ofthe plating system 1 can be improved.

[0081] of the housing 31 of the process station 3, a housing 31 adisposed at a position facing to the carrier station 2 is provided, asshown in FIG 3, with three openings G1 through G3 that can be opened.

[0082] Among these, the opening G1 is disposed at a positioncorresponding to a middle susceptor 36 disposed between the platingunits M1 and M2 disposed on the lower tier side. The opening G1 is usedwhen an untreated wafer W taken out of the carrier cassette C by thesub-arm 22 is sent in the process station 3. When sending in the waferW, the opening G1 is opened, the sub-arm 22 extending the wafer holder22 a holding the untreated wafer W to dispose the wafer W on the middlesusceptor 36. The main-arm 35 makes access to the middle susceptor 36,holds the wafer W disposed on the middle susceptor 36 and transfers intothe treatment unit such as the plating units M1 through M4.

[0083] The remaining openings G2 and G3 are disposed at positionscorresponding to the cleaning unit 70 disposed on a side closer to thecarrier station 2 in the treatment space S.

[0084] The sub-arm 22 makes direct access through one of these openingsG2 and G3 to the cleaning unit 70 disposed on the upper tier side toreceive a treated wafer W. Accordingly, the wafer W cleansed in thecleaning unit 70 is prevented from touching with the stained main-arm 35to be contaminated.

[0085] Furthermore, in the treatment space S, an airflow is formeddirecting from above to below. A clean air supplied from outside of theplating system 1 is fed from an upper portion of the treatment space S,flowing through the cleaning unit, plating units M1 through M4 tooutside the plating system 1 from the base portion of the treatmentspace S.

[0086] By thus flowing a clean air from up to down in the treatmentspace S, the air is prevented from flowing from the plating units M1through M4 on the lower tier side to the cleaning unit 70 on the uppertier side. Accordingly, the cleaning unit 70 side can always maintain aclean atmosphere.

[0087] Furthermore, the interiors of the respective treatment units suchas the plating units M1 through M4 and cleaning unit 70 are maintainedlower in pressure than in the treatment space S. Accordingly, the air inthe treatment space S flows from the treatment space S side to theinsides of the respective treatment units, therefrom being exhaustedoutside the plating system 1. Accordingly, contamination can beprevented from diffusing from the treatment unit side into the treatmentspace S.

Detailed Explanation of Plating Unit

[0088]FIG. 5 is a vertical section of a plating unit M1. As shown inFIG. 5, an entire plating unit M1 is covered by an airtightly structuredhousing 41. The housing 41 is also made of corrosion resistant materialsuch as resin or the like.

[0089] The interior of the housing 41 is partitioned, by a separator 42having a built-in exhaust path, in two of a first treatment portion Aabove the separator 42 and a second treatment portion B thereunder 42.The separator 42 prevents the contamination from diffusing from thesecond treatment portion B side to the upper first treatment portion Aside.

[0090] In the center of the separator 42, there is disposed a passageopening 65. Through the passage opening 65, a wafer W held by a driver48 described below comes and goes between the first and second treatmentportions A and B.

[0091] To the housing at a boundary between the treatment portions A andB, an opening and a gate valve 66 to open the opening are disposed. Byshutting the gate valve 66, the interior of the plating unit M1 isshielded from the exterior treatment space S, thereby the contaminationbeing prevented from diffusing from the plating unit M1 to the exteriortreatment space S.

[0092] Furthermore, the plating units M1 through M4 each are configuredto be operated independently from each other and to be separatelydetached from the plating system 1. Accordingly, one of the platingunits M1 through M4 can be stopped operating to be replaced by anotherplating unit. As a result, maintenance can be implemented with ease foreach unit.

[0093] To the first treatment portion A, a driver 48 as a substrate holdmechanism is disposed to hold the wafer W approximately level to spin.The driver 48 is configured of a holder 49 for holding the wafer W and amotor 50 for spinning the wafer W together with the holder 49 in anapproximately level plane. To a cover of the motor 50, a support beam 51is attached to support the driver 48. One end of the support beam 51 isattached through a guide rail 52 to an inner wall of the housing 41 tobe elevated. The support beam 51 is further attached through a cylinder53 to the housing 41. By driving the cylinder 53 and motor 50, thedriver 48 can be moved up and down.

[0094] As shown in FIG. 5, the driver 48 moves the wafer W up and downbetween essentially following four positions (I) through (IV). The fourpositions are a transfer position (I) for transferring in and out thewafer W, a cleaning position (II) for cleaning a surface being treatedon a lower surface side of the wafer W, a spin dry position (III) forimplementing the spin drying described below, and a plating position(IV) for plating the wafer W in an immersed state in a plating solution.

[0095] Inside the driver 48, an elevation mechanism (not shown in thedrawing) is disposed to elevate the wafer W alone. By actuating theelevation mechanism, without changing a height of the driver 48 itself,only a height of the wafer W can be changed inside the driver 48.

[0096] The elevation mechanism is actuated when a cathode contact 164,an electric contact, which applies a voltage when coming into contactwith a lower surface periphery of the wafer W, and the wafer W come intoor leave from contact. For instance, when cleaning the cathode contact164, the elevation mechanism raises the wafer W to expose a contactsurface, thereby water ejected from a nozzle cleansing the cathodecontact 164 with ease. A sealing portion 166 comes into contact with aperiphery of the wafer W to prevent the treatment solution fromintruding into the holder 49.

[0097] To the second treatment portion B, a plating solution bath 54 isdisposed immediately below the driver 48 to accommodate a platingsolution for copper plating such as for instance copper sulfate.

[0098] The plating solution bath 54 is structured in a double bath,outside an inner bath 54 a an outer bath 54 b being disposedapproximately concentrically. A height of the inner bath 54 a isdetermined so that a liquid level of the plating solution when the innerbath 54 a is filled by the plating solution is higher than that of thewafer W in the plating position (IV).

[0099] An ejection tube 55 extends from an approximate center of a basein the inner bath 54 a to an approximate midway in a depth direction toeject the plating solution from the base of the inner bath 54 a to theupper portion thereof. In the surroundings of the ejection tube 55, anelectrode 56 is disposed so that functions as an anode when implementingelectrolytic plating. Between an end periphery of the ejection tube 55and the inner bath 54 a, a membrane 57 is disposed to prevent impuritiesmingling from the electrode 56 during electrolytic plating from floatingabove the liquid level of the plating solution to disturb the plating.

[0100] At positions out of center of the base in the inner bath 54 a,there are disposed circulation piping 58 and 59 for circulating theplating solution. The plating solution inhaled by the circulation piping59 is exhaled from the circulation piping 58 by means of a pump notshown in the drawing.

[0101] Between the outer bath 54 b and an exterior surface of the innerbath 54 a, there is formed a passage 62 therein the plating solutionflows. Furthermore, to the base of the outer bath 54 b, piping 61 isconnected to return the plating solution flowed in the passage 62 in theinner bath 54 a. The piping 61 is connected through the pump 60 to theejection tube 55. By actuating the pump 60, the plating solutionoverflowed from the inner bath 54 a into the passage 62 and piping 61 isejected from the ejection tube 55 to return again into the inner bath 54a.

[0102] To the first treatment portion A, a mechanism such as a cleanroom is disposed to circulate a stream of clean air.

[0103] That is, at the uppermost of the housing 41, an air nozzle 43 isdisposed to flow the air downwardly toward the first treatment portionA, to the air nozzle 43 air feed piping 44 being connected to feed theair. An upstream side in an airflow direction of the air feed piping 44is connected to an air passage 45 embedded in the uppermost side in theseparator 42.

[0104] On an upper surface of the separator 42, an air inlet 46 fortaking in the air is formed to take in the air that has flowed down inthe first treatment portion A. Furthermore, in the middle of the airfeed piping 44, a fan (omitted from showing) or a compressor 37 isdisposed to flow the air, the air taken in at the air inlet 46 beingsent through the air feed piping 44 to the air nozzle 43. To the airnozzle 43, a filter 47 is disposed to remove dust or dirt in the air.Clean air leaving the air nozzle 43 is inhaled in the air inlet 46 ofthe separator 42 to form a down flow in the first treatment portion A.Thus, by flowing the cleansed air in a downward direction in thedrawing, the inside of the treatment portion A is maintained in a cleanatmosphere.

[0105] On the other hand, a space in the second treatment portion Bbelow the separator 42 is independent from that in the first treatmentportion A. Accordingly, the air flowing in the first treatment portion Adoes not flow into the second treatment portion, and the air in thesecond treatment portion does not flow into the first treatment portionA, on the contrary. By thus preventing the air from flowing from thetreatment portion B side to the treatment portion A side, an atmospherein the treatment portion A is maintained clean.

[0106] Below the separator 42, an exhaust 64 is disposed. The exhaust 64is connected to a not shown exhaust system. Minute particles or the likeof the plating solution scattered in the second treatment portion B areinhaled in the exhaust 64 to be exhausted together with the exhaustoutside the plating system 1. Thus, by exhausting the minute particlescontained in the air in the treatment portion B outside the platingsystem 1, the atmospheres in the plating units M1 through M4 and theplating system 1 are maintained clean.

[0107] To the separator 42, at the inner wall lower portion of thepassage opening 65, a plurality of cleaning nozzles 162 are disposed. Toa lower surface of the wafer W stopped at the cleaning position, fromthe cleaning nozzles 162, for instance purified water is ejected tocleanse.

[0108] At the portion of the passage opening 65, an air curtain may beformed in a level direction. For instance, on one side of the separator42 a nozzle is disposed to blow air in plane, and on the opposite sideof the separator 42 an inlet is disposed to inhale the air gone past theupper portion of the plating solution bath 54. The air inhaled by theinlet is exhausted outside the plating system 1.

[0109] By thus forming an air curtain at a boundary between thetreatment portions A and B, mist containing the plating solution in theplating solution bath 54 can be prevented from diffusing into thetreatment portion A side.

[0110] Furthermore, in the plating unit M1, a temperature controller orhumidity controller may be disposed. By controlling the temperature orhumidity in the plating unit M1, the mist of the plating solution or thelike, resultantly the contamination of the air in the plating unit M1can be prevented from occurring.

Detailed Explanation of Cleaning Unit

[0111]FIGS. 6 and 7 are vertical sections showing schematically astructure of a cleaning unit 70 involving the present embodiment.

[0112] In the cleaning unit 70, in a housing 71 of approximatelyparallelepiped box, a fixed cup 72 is disposed. Inside the fixed cup 72,a spinning cup 73 and a lifter 74 are disposed.

[0113] In the housing 71, an opening 75 facing the main-arm 35 and anopening 77 facing the sub-arm 22 side are disposed. To the openings 75and 77, gate valves 76 and 78 are disposed to open and shut these,respectively.

[0114] By shutting the gate valves 76 and 78, the cleaning unit 70 isshielded from the treatment space S, thereby contaminated air beingprevented from diffusing from the interior of the cleaning unit 70 tothe treatment space S.

[0115] Furthermore, in the cleaning unit 70, a pressure controller formaintaining a lower pressure therein than the outside thereof, ortemperature or humidity controller may be disposed. By maintaining thepressure inside thereof lower than that in the treatment space S, themist such as the plating solution or the like can be prevented fromdiffusing from the cleaning unit 70 to the outside thereof. Furthermore,by controlling the temperatures and humidity, the mist of the platingsolution or the like can be prevented from being generated.

[0116] A spinning cup 73 rotates holding the wafer W. On each of upperand lower surfaces of the rotating wafer W, cleaning fluid is suppliedto cleanse the wafer W.

[0117] On a sidewall of the spinning cup 73, a chuck member 92 isdisposed to fix the wafer W. As shown in a small circle of FIG. 6, thechuck member 92 varies in its inclination with respect to the wafer W.As shown in a small circle A of FIG. 6, when the spinning cup 73 standsstill, a tip end 92 a of the chuck member 92 separates itself from aperiphery of the wafer W, thereby enabling to dispose the wafer Wdetachable. On the other hand, as shown in a small circle B of FIG. 6,when the spinning cup 73 is in rotation, according to the centrifugalforce, the tip end 92 a of the chuck member 92 presses against theperiphery of the wafer W inwardly in a radius direction. Thereby, thewafer W is fixed.

[0118] An edge remover 101 disposed above the spinning cup 73 moveshorizontally in a radius direction of a circle having a center at arotation axis 100 of the spinning cup 73. The edge remover 101sandwiches the wafer W to cleanse the periphery thereof.

[0119] That is, when cleansing the periphery of the wafer W as shown inFIG. 7, the edge remover 101 makes access to the wafer W lifted by thelifter 74 to sandwich the periphery of the wafer W. Then, from pipingdisposed inside a lower side member 104 of the edge remover 101, anaqueous solution of hydrofluoric acid is supplied. The piping disposedinside an upper side member 103 sucks the above aqueous solution ofhydrofluoric acid, thereby enabling to cleanse the periphery of thewafer W.

Detailed Explanation of Annealing Unit

[0120]FIGS. 8 and 9 are plan and sectional views showing a configurationof an annealing unit involving the present embodiment. In FIG. 8, forthe purpose of showing the interior, a level shield plate 112 isomitted. A treatment chamber 110 of the annealing unit is configured ofboth sidewalls 111 and a level shield plate 112. Furthermore, in frontsurface (main-arm 35 side) and rear surface sides of the treatmentchamber 110, openings 110A and 110B are formed, respectively. In thecentral portion of the level shield plate 112, a circular opening 113 isformed, inside thereof 113 a disc-like susceptor 120 being disposed.

[0121] In the susceptor 120, for instance three through holes 121 aredisposed, inside of each through hole 121 there being inserted a liftpin 122 unengaged. When loading and unloading the wafer W, the lift pin122 projects or elevates above a surface of the susceptor 120 to deliverthe wafer W between the wafer holder 35 a of the main-arm 35.

[0122] Along an exterior periphery of the susceptor 120, a shutter 126consisting of a ring-like band plate in which for instance with aseparation of 2° in a circumferential direction, a number of air holes124 are formed is disposed. The shutter 126 is usually in retreat at aposition below than the susceptor 120. When implementing heat treatmentsuch as annealing, as shown in FIG. 9, the shutter 126 ascends to aposition higher than a upper surface of the susceptor 120 to form aring-like sidewall between the susceptor 120 and a cover body 128. Adownflow of air or inert gas such as nitrogen sent in from a not showngas supplier is effected to flow from the air holes 124 uniformly alonga circumferential direction into an annealing unit.

[0123] In the center of the cover body 128, an exhaust 128 a is disposedto exhaust a gas liberated from the surface of the wafer W during theheat treatment, thereto 128 a an exhaust pipe 130 being connected. Theexhaust pipe 130 is communicated with a duct (omitted from showing inthe drawing) on a front face side of the unit (main-arm 35 side).

[0124] A machine chamber 115 is formed of the horizontal shield plate112, both sidewalls 111 and the base plate 114. Inside the machinechamber 115, a susceptor support plate 116, a shutter arm 117, a liftpin arm 118, a cylinder 119 for driving the shutter arm to elevate and acylinder 125 for driving the lift pin arm to elevate are disposed.

[0125] As shown in FIG. 8, in the susceptor 120, at surface positionsthereof 120 where the periphery of the wafer W is disposed, a plurality,for instance four, of wafer W guide support projections 131 aredisposed.

[0126] Inside the susceptor 120, an electric heater (not shown in thedrawing) such as Nichrome wire or the like is disposed. The electricheater is heated to maintain the susceptor 120 at a prescribedtemperature.

Flow of Treatment in Plating System 1

[0127]FIG. 10 is a flow chart showing a flow in an entire plating system1.

[0128] As shown in FIG. 10, the wafer W is transferred in the platingsystem 1 (step 1) to implement the plating and cleaning (step 2 to 3),thereafter being transferred out of the plating system 1 (step 4).

[0129] The wafer W is transferred in the plating system 1 in thefollowing way.

[0130] On the susceptor 21, by the use of a transfer robot not shown inthe drawing, the carrier cassette C accommodating one lot, for instance25 sheets, of untreated wafers W is disposed.

[0131] The sub-arm 22, after confirming that the untreated wafers W areset in the carrier cassette C, moves in front of the carrier cassette C.The sub-arm 22 extends the wafer holder 22 a into the carrier cassette Cto take out the untreated wafer W accommodated therein, thereafterdisposing on the middle susceptor 36 in the process station.

[0132] In the neighborhood of the susceptor 21, an alignment controller(omitted from showing in the drawing) may be disposed to align, beforetransferring the wafer W onto the sub-arm 22 or middle susceptor 36 a, adirection (alignment) of the wafer W by means of the alignmentcontroller.

[0133] When the untreated wafer W is disposed on the middle susceptor36, the main-arm 35, conceiving the disposition of the wafer W, startsactuating and makes access to the middle susceptor 36 to receive theuntreated wafer W. The main-arm 35 that has received the untreated waferW makes access to the plating unit, for instance the plating unit M1,disposed on the lower tier side of the treatment space S to send theuntreated wafer W in the plating unit M1.

Detailed Explanation of Plating Process

[0134] In the following, with reference to FIGS. 11 through 24, a flowof treatment in the plating unit M1 will be explained.

[0135]FIG. 11 is a flow chart showing a flow of plating processimplemented in the plating unit M1, FIGS. 12 through 23 being diagramsshowing schematically the respective steps of the plating.

[0136] The main-arm 35, after receiving the untreated wafer W from themiddle susceptor 36, makes access to the plating unit M1. That is, thegate valve 66 of the plating unit M1 is opened, the main-arm 35 holdingthe untreated wafer W proceeding in the first treatment portion A. Themain-arm 35 delivers the untreated wafer W to the holder 49 waiting inthe transfer position (I) as shown in FIG. 12 (step 2 (1)). At thattime, the plating solution bath 54 is full of the plating solution.

[0137] At that time, the interior of the plating unit M1 is maintainedat a pressure lower than that in the treatment space S. Accordingly,when the gate valve 66 is opened, though the air flows from thetreatment space S side toward the inside of the plating unit M1, themist including the plating solution does not flow out of the inside ofthe plating unit M1 to contaminate the treatment space S.

[0138] After having set the untreated wafer W in the holder 49 of thedriver 48, the gate valve 66 is shut, the cylinder 53 being driven tolower the wafer W to the plating position (IV) (step 2 (2), FIG. 13).

[0139] By the lowering operation, a surface being treated on the lowersurface side of the wafer W held by the holder 49 comes into contactwith the liquid level of the plating solution in the plating solutionbath 54. When the wafer W and the liquid level of the plating solutioncoming into contact, sometimes there form air bubbles on the surface ofthe wafer W. When plating the wafer W with air bubbles on its surface, aplating layer formed on the surface of the wafer W is likely to benon-uniform.

[0140] Accordingly, with the wafer W being in contact with the liquidlevel of the plating solution, the motor 50 of the driver 48 is actuatedto spin the wafer W in an approximately level plane, thereby degassingfrom the surface of the wafer W (step 2 (3), FIG. 14).

[0141] After sufficiently degassing, with the same height maintained, arotation speed of the motor 50 is decreased, followed by an applicationof a voltage between the wafer W and the electrode 56 in the platingsolution bath 54 to start plating (step 2 (4)).

[0142] When, after the passage of a prescribed time, the plating layerof a sufficient thickness is formed on the wafer W, the application ofthe voltage is ceased to stop the formation of the plating layer. Uponopening a valve V1, a pump 67 for pumping out is simultaneously actuatedto return the plating solution into a tank 68, thereby lowering theliquid level in the plating solution bath 54 (step 2 (5)).

[0143] Furthermore, the driver 48 is raised to move the wafer W up tothe spin dry position (III). In this state, the motor 50 is actuated tospin the wafer W in a horizontal plane to spin dry (step 2 (6), FIG.15).

[0144] When almost all of the plating solution is removed from the waferW due to the spin dry, the driver 48 is raised up to the cleaningposition (II) (step 2 (7), FIG. 16).

[0145] Next, in this state, while driving the motor 50 to spin the waferW, purified water is ejected from a cleaning nozzle 162 toward a lowersurface of the wafer W to cleanse the lower surface of the wafer W (step2 (8), FIG. 17).

[0146] Having completed the cleaning of the lower surface of the waferW, with the height of the holder 49 maintained as it is, by means of anot shown elevator, the wafer W in the holder 49 is a little raised. Thewafer W is raised up to a height where purified water ejected from thecleaning nozzle 162 comes into contact with the cathode contact 164. Inthis state, purified water is ejected from the cleaning nozzle 162 tocleanse the surface of the cathode contact 164 (step 2 (9), FIG. 18).

[0147] After the cleaning of the cathode contact 164 is over, the waferW is lowered down to a height where the wafer W comes into contact withthe cathode contact 164 (FIG. 19), and furthermore the driver 48 beinglowered so that the wafer W comes to the spin dry position (III) (step 2(10), FIG. 20). Still furthermore, the motor 50 is actuated to spin dry,thereby removing moisture from the wafer W (step 2 (11), FIG. 21)).

[0148] After the spin dry is over, the driver 48 is raised so that thewafer W comes to the transfer position (I) (step 2 (12), FIG. 22). Whilemaintaining the wafer W in this position, the gate valve 66 is opened totransfer out, by means of the main-arm 35, the wafer W that is treatedin the plating unit M1 (step 2 (13), FIG. 23).

[0149] During the degassing or plating, when bringing the wafer W andthe plating solution into or out of contact, or during the spin drying,or during the cleaning, the plating solution scatters outside theplating solution bath 54. However, since the air in the treatmentportion B therein the plating solution bath 54 is disposed is alwaysevacuated during the treatment, the plating solution scattered from theplating solution bath 54 is evacuated together with the air. As aresult, the treatment portion B is not filled with the mist of theplating solution or the mist containing the plating solution does notdiffuse from the interior of the treatment portion B into the treatmentportion A or the treatment space S.

[0150] In the last spin drying, the drying may be stopped at a statewhere the wafer W is not completely dried, thereby leaving moisture acertain extent thereon. In this case, the wafer W of which surface is alittle wet with moisture is transferred from the plating unit M1. As aresult, it is prevented from occurring that moisture is dried and thecomponents of the plating solution remains as particles on the surfaceof the wafer W.

[0151] After the completion of the plating step at the plating unit M1,the wafer W is transferred to a treatment unit therein a succeedingtreatment is implemented. For instance, the wafer W is transferred inone of other plating units M2 through M4 where the plating solutiondifferent in composition from that of plating unit M1 is used toimplement the succeeding treatment.

[0152] In the course of transferring the wafer from the plating unit M1to one of subsequent treatment units, for instance, the plating units M2through M4, or the cleaning unit as the second treatment unit, as needsarise, the main-arm 35, while holding the wafer W, turns upside downfront and back surfaces thereof W. For instance, it is such a case when,after a plating layer is formed on a lower surface side of the wafer Wat the plating unit M1, the plated surface is directed upwardly tocleanse. Thus, during the transfer of the wafer W, the wafer W can beturned upside down on the main-arm 35. Accordingly, there is nouselessness in the step of the treatment.

[0153] When a series of plating steps is over, the main-arm 35 makesaccess into the last one of the plating units M1 through M4 to take outthe plated wafer W.

[0154] Thereafter, the main-arm 35 moves the wafer holder 35 a holdingthe wafer W to the upper portion of the treatment space S to send thewafer W in the cleaning unit 70 disposed on the upper tier side of theplating units M1 through M4.

[0155] At that time, in the treatment space S, a down flow is formed inwhich, from above to below in the drawing, a clean air flows down. As aresult, the air does not flow from the plating units M1 through M4 onthe lower tier side to the cleaning unit 70 side on the upper tier side.Accordingly, an atmosphere in the neighborhood of the cleaning unit 70in the treatment space S is maintained cleaner than that in theneighborhood of the plating units M1 through M4.

Detailed Explanation of cleaning Process

[0156] In the following, the cleaning carried out in the cleaning unit70 as the second treatment unit will be explained.

[0157]FIG. 24 is a flow chart (flow chart 3) showing a flow of thecleaning step carried out in the cleaning unit 70.

[0158] When the wafer holder 35 a of the main-arm 35 holding the platedwafer W approaches the gate valve 76 of the cleaning unit 70, the gatevalve 76 is opened to expose the opening 75 of the housing 71. Themain-arm 35 proceeds from the opening 75 inside the cleaning unit 70 totransfer the wafer W to a position immediately above a lift plate 93 ofthe lifter 74.

[0159] In this state, the lifter 74 is actuated to raise the lift plate93 to receive the wafer W from the wafer holder 35 a of the main-arm 35(step 3 (1)). Furthermore, the main-arm 35 draws in the wafer holder 35a, thereby the transfer in of the wafer W from the main-arm 35 to thecleaning unit 70 being over.

[0160] When transferring in the wafer W, the gate valve 76 is opened.However, the interior of the cleaning unit 70 is maintained lower inpressure than in the outside treatment space S. Accordingly, there is nochance that the air flows out of the cleaning unit 70 to the treatmentspace S to contaminate the treatment space S.

[0161] After the main-arm 35 retreats outside the cleaning unit 70, thelift plate 93 ascends further to hold the wafer W at a height betweenthe upper and lower side members 103 and 104 of the edge remover 101(step 3 (2)).

[0162] In this state, the edge remover 101 moves toward a radiusdirection of the wafer W to approach the periphery of the wafer W (step3 (3)).

[0163] When the edge remover 101 approaches a position that sandwichesthe periphery of the wafer W, the edge remover 101 stops. A cleaningfluid is ejected to the wafer W from piping embedded with an outwardlyslanting direction in the lower side member 104. At the same time,piping embedded in the upper side member 103 sucks the cleaning fluid.When rotating the lifter 74 in this state, the cleaning fluid issupplied only to the periphery of the wafer W, thereby the so-callededge cleaning being implemented (step 3 (4)). FIG. 7 is a verticalsection depicting schematically a situation of the edge cleaning.

[0164] When the edge cleaning is over, once the lifter 74 is stoppedrotating. The edge remover 101 is moved outside in a radius direction ofthe wafer W to separate itself from the wafer W (step 3 (5)).

[0165] Next, the lifter 74 is lowered to the lowermost position to beaccommodated in the spinning cup 73 (step 3 (6)). The wafer W disposedon the lifter 74, when lowering the lifter 74, is engaged with a step atthe tip end of the upper opening 91 of the spinning cup 73 to be held(step 3 (7)).

[0166] However, as already shown in the small circle A of FIG. 6, beforethe spinning cup 73 is spun, a plurality of chuck members 92 disposed onthe sidewall of the spinning cup 73 are approximately verticallydirected. That is, the chuck members 92 do not press against theperiphery of the wafer W, the wafer W held on the spinning cup 73 beingsimply put on. Accordingly, the wafer W can be lifted up with ease whenthe lifter 74 exerts an upward force in a vertical direction.

[0167] Next, while spinning the spinning cup 73 together with the waferW, from a shower nozzle (omitted from showing in the drawing) disposedabove the wafer W, purified water is supplied on the wafer W to watercleanse the upper surface of the wafer W (step 3 (8)). At that time, asshown in the small circle B of FIG. 6, due to the spin of the spinningcup 73, the upper portion of the chuck member 92 inclines inwardly, thetip end thereof pressing against the wafer W inwardly in a radiusdirection. As a result, the wafer W is solidly fixed in the spinning cup73.

[0168] After the completion of the purified water cleaning of the uppersurface of the wafer W, the shower nozzle stops ejecting the purifiedwater. Thereafter, in the lifter 74 the cleaning fluid is supplied. Thecleaning fluid is supplied from the inside of the lifter 74 through thethrough holes 93 a on the upper surface of the lift plate 93 to thelower surface side of the wafer W. With the cleaning fluid, chemicalcleaning is implemented on the lower surface side of the wafer W (step 3(9)).

[0169] When the chemical cleaning of the lower surface of the wafer W isover, the cleaning fluid is stopped supplying to the lifter 74. In thisstate, the spinning cup 73 is rotated with a high rotational speed tothrow off the cleaning fluid and moisture, thereby so-called spin-dryingbeing implemented (step 3 (10)).

[0170] After the spin-drying is over, the spinning cup 73 is stoppedrotating, the lifter 74 being raised to lift up the cleansed wafer W tothe transfer position (I) (step 3 (11)).

[0171] During the above cleaning process, in the cleaning unit 70, thecleaning water or cleaning fluid is splashed. However, the interior ofthe cleaning unit 70 is always exhausted outside the plating system 1.Accordingly, the splashed cleaning water or cleaning fluid is exhaustedtogether with the air outside the plating system 1. As a result, it canbe prevented from occurring that the interior of the cleaning unit 70becomes full of the mist of the splashed cleaning water or cleaningfluid, and the mist diffuses in the treatment space S.

[0172] In this state, the gate valve 76 on the main-arm 35 side of thehousing 71 is opened. After the gate valve 76 is opened to expose theopening 75, the main-arm 35 is effected to proceed in the cleaning unit70. Furthermore, the wafer holder 35 a of the main-arm 35 is extended upto the lower side of the lift plate 93 that has lifted up the wafer W.Thereafter, the lifter 74 is lowered to deliver the wafer W from thelift plate 93 to the main-arm 35 side. Subsequently, the main-arm 35holding the wafer W is effected to retreat from the cleaning unit 70,thereby transferring out the wafer W (step 3 (12)).

Detailed Explanation of Annealing Process

[0173] After the cleaning by means of the cleaning unit 70 is over, as asubsequent treatment, for instance annealing as a third treatment isimplemented. The annealing is implemented by disposing the wafer W on aso-called hot plate for a prescribed time period.

[0174] On the susceptor 120 of the heating unit as the third treatmentunit such as shown in FIGS. 9 and 10, the wafer W is disposed for aprescribed time period to anneal.

[0175] When disposing the wafer W on the susceptor 120, the wafer holder35 a of the main-arm 35 holding the wafer W is extended immediatelyabove the susceptor 120 before the lift pin 122 is raised. As a result,the wafer W is delivered from the main-arm 35 side to the heating unitside. In delivering the wafer W from the heating unit side to themain-arm 35 side, the opposite thereof is carried out.

[0176] When the annealing is over, once more the main-arm 35 receivesthe treated wafer W. The treated wafer W is, through the middlesusceptor 36, or the cleaning unit 70, delivered from the main-arm 35 tothe sub-arm 22.

[0177] The treated wafer W delivered to the sub-arm 22 is accommodatedin the carrier cassette C. Thus, a series of treatment is over.

[0178] As explained above, in the plating system 1 involving the presentembodiment, the process stations are disposed in multi-tiers to disposea plurality of treatment units in a vertical direction in the treatmentspace. Accordingly, in a small occupation area, various kinds oftreatments can be implemented, resulting in a high area efficiency ofthe plating system 1.

[0179] Furthermore, in the treatment space, each of the plating units M1through M4 is accommodated in the closed housing 41 to maintain anisolated atmosphere by means of respectively independent airflow. As aresult, between the plating units each, treatment atmospheres do notinterfere with each other. Accordingly, a number of plating units can bedisposed in a small treatment space, resulting in improvement of utilityand efficiency of the area in the plating system 1.

[0180] Furthermore, since each plating unit is maintained in an isolatedatmosphere, a plating unit that uses the plating solution bathaccommodating a plating solution of different composition can beadjacently disposed. Accordingly, various plating can be implemented ina small space.

[0181] Furthermore, in each plating unit, the interior thereof islargely partitioned in two of upper and lower treatment portions. Thefirst treatment portion A having the opening for transferring isdisposed on the upper side, the second treatment portion B having theplating solution bath on the lower side.

[0182] A clean airflow is circulated to maintain a clean atmosphere inthe treatment portion A, in the clean atmosphere the wafer W beingtransferred in and out. On the other hand, an environment where theplating solution tends to scatter is confined into the second treatmentportion B on the lower side of the separator 42, therein B an airflowseparate from that in the first treatment portion A being circulated.Accordingly, there is no risk of contaminated particles or the likegoing from the first treatment portion A into the second treatmentportion B to mingle.

Modification Example of the First Embodiment

[0183] The present invention is not restricted to the above embodiment.In the above embodiment, only one surface of the wafer W is plated.However, for instance, with a plurality of different liquid treatmentbaths and by turning upside down the wafer W, different liquid treatmentcan be applied between the front and back surfaces of the wafer W.

[0184] Still furthermore, to the above first treatment portion A, thefilter removing only minute particles is disposed. However, a chemicalfilter may be further disposed to remove acids, organic substances andalkali ions.

[0185] Furthermore, in the neighborhood of the opening for transferringin and out of treatment units each, an air curtain due to a nitrogen gasmay be further formed.

[0186] In addition, the air circulating in the first and secondtreatment portions A and B may be controlled in temperature and humiditythereof.

[0187] Furthermore, the main-arm 35 may be provided with a functioncapable of turning upside down the wafer W in the middle oftransferring.

[0188] Still furthermore, in the above embodiment, on the upper tierside of the treatment space S, other than the cleaning unit as thesecond treatment unit, the annealing unit as the third treatment deviceis disposed to explain. However, as the third treatment unit, atreatment unit other than the annealing unit, for instance apretreatment unit for surface treating the wafer W before the plating ora post-treatment unit for treating the plated wafer W may be disposed.

[0189] Still furthermore, in the above embodiment, the wafer W is takenfor an example to explain. The present invention can be applied as theplating system for a glass substrate for LCD.

[0190] Furthermore, in the above embodiment, the plating unit isdisposed on the lower tier side. However, needless to say, any treatmentunit capable of implementing treatment in liquid phase other thanplating unit can be used.

Second Embodiment

[0191] In the following, a plating system involving a second embodimentof the present invention will be explained.

[0192] Of the plating system involving the present embodiment, thecontents overlapping with the first embodiment will be omitted fromexplaining.

[0193] In the plating system involving the present embodiment, on theupper tier side of the treatment space, only the cleaning unit 70 isdisposed. Furthermore, after the cleaning of the wafer W is over, thesub-arm 22 makes direct access into the cleaning unit 70 to transfer outthe wafer W.

[0194] By configuring thus, the wafer W that has been cleansed to beclean, without going through the lower tier side of the treatment spaceS that tends to be contaminated with ease, is delivered to the sub-arm22. As a result, when transferring out, there is no risk ofcontamination adhering on the treated wafer W.

Third Embodiment

[0195] Next, a method for manufacturing, by the use of the platingsystem 1 involving the present invention, a semiconductor device with novoid in the plating layer will be explained.

[0196] On a surface of a wafer, there is formed minute unevenness.Accordingly, first a barrier metal layer is formed, thereon copper orthe like being precipitated to form a conductor layer called a seedlayer. By implementing electrolytic plating through the seed layer, aplating layer that is an interconnection layer is made of copper.

[0197] However, when trying to plate on the seed layer to form a thicklayer at a time, in plating on the seed layer to form a copper layer,sometimes there may be formed holes called void or seam in the platinglayer. When the holes are formed in the plating layer, there islikelihood of occurrence of disconnection in an interconnection layer orlowering of quality and yield of the semiconductor devices due tovariation of electrical resistance.

[0198] Accordingly, it is strongly demanded to provide a method formanufacturing a semiconductor device that does not contain holes in theplating layer.

[0199] Furthermore, properties of the conductor layer formed on the seedlayer are intimately related with a crystallographic direction of thecopper layer constituting the conductor layer, the crystallographicdirection of the copper layer being necessary to be aligned in adefinite direction.

[0200] However, the crystallographic direction of the plating layer isdependent on a structure of the seed layer thereunder. Accordingly, itis difficult to align the crystallographic direction in the platinglayer alone.

[0201] Accordingly, it is strongly demanded to provide a manufacturingmethod of a semiconductor device that is provided with a conductor layerof which crystallographic direction is aligned in a prescribeddirection.

[0202]FIG. 25 is a flow chart showing a flow of a manufacturing processof a semiconductor device involving the present embodiment, FIGS. 26Athrough D being vertical sections showing schematically a situation whenthe semiconductor device is manufactured. In the following, withreference to FIGS. 25 and 26, the respective steps of the manufacturingmethod of the semiconductor device involving the present embodiment willbe explained.

[0203] The sub-arm 22 makes access into the carrier cassette C disposedon the susceptor 21 to take out an untreated wafer W and deliver to themain-arm 35. The main-arm 35 delivers the wafer W to the holder 49 inthe plating unit M1, thereby the transfer of the wafer W being over(step 4 (1)).

[0204] In the wafer W being transferred into the plating unit M1, asshown in FIG. 26A, on a surface of a wafer W 301 thereon a groove isformed a barrier metal layer not shown in the drawing is formed.Thereon, a seed layer 302 consisting of a thin copper layer is formed bymeans of PVD or CVD.

[0205] Subsequently, in the plating unit M1, a first plating isimplemented (step 4 (2)).

[0206] In the first plating that is implemented in this step, whenputting a total depth of a contact hole and a total height of a platinglayer formed on the seed layer, hand H, respectively, it is preferablefor a thickness D of a plating layer formed in the first plating to be(½)H≦D<H. The first plating is preferable to be implemented by sending arelatively small electric current, for instance, approximately 0.5 ASD(Ampere per Square Decimeter). It is because mild formation of theplating layer can prevent holes such as voids or seams from forming.

[0207] When the first plating is over thus, as shown in FIG. 26B, afirst plating layer 303 is formed.

[0208] When the first plating is over, the main-arm 35 makes access intothe plating unit M1 to take out the treated wafer W, followed bytransferring to an annealing unit (step 4 (3)).

[0209] When the transfer to the annealing unit is over, in the annealingunit, a first annealing is implemented (step 4 (4)).

[0210] As a result of the first annealing, the crystallographicdirection of the plating layer 303 is aligned.

[0211] After the first annealing is over, once more through the main-arm35, the treated wafer W is again transferred in the plating unit M1(step 4 (5)).

[0212] After the wafer W is once more set in the plating unit M1, asecond plating is carried out (step 4 (6)), as shown in FIG. 26C, on theplating layer 303, a new plating layer 304 being further formed.

[0213] At that time, in the plating layer 303 under the plating layer304, due to the first annealing the crystallographic direction thereofis aligned. Accordingly, the plating layer 304 is liable to be alignedin its crystallographic direction with that of the plating layer 303.

[0214] Accordingly, the second plating even under the condition of arelatively large electric current, for instance approximately 2.0 ASD,forms the holes with difficulty. Since the second plating can beimplemented thus by sending a relatively large electric current, platingspeed is heightened to form a thicker plating layer in a short time. Inthe second plating, the plating layer 304 is further formed on the firstplating layer 303 to be a plating layer of a total thickness H on theseed layer.

[0215] After the second plating is over, once more the wafer W istransferred into the annealing unit by means of the main-arm 35 (step 4(7)), here the second annealing being implemented (step 4 (8)).

[0216] Due to the second annealing, an internal state of the platinglayer 304 is more stabilized.

[0217] After the second annealing is over, the wafer W is transferredout of the annealing unit by means of the main-arm 35 (step 4 (9)), thusa series of treatment being over.

[0218] Thus, in the manufacturing method of a semiconductor deviceinvolving the present embodiment, after the formation of the firstplating layer, the step of annealing is implemented to align thecrystallographic direction of the first plating layer, thereafter thesecond plating being implemented.

[0219] Accordingly, the second plating layer is formed in accordancewith the crystallographic direction aligned in the first plating layer.In addition, since the second plating layer is formed in accordance withthe crystallographic direction of the first plating layer, in the secondplating layer, the holes are generated with more difficulty than in thefirst plating layer. Furthermore, due to the use of larger electriccurrent, the second plating layer can be formed with a growth ratelarger than that of the first plating layer.

[0220] Still furthermore, by annealing after the formation of the secondplating layer, an internal structure of the second plating layer can bestabilized to result in an improvement of quality of the plating layer.

Fourth Embodiment

[0221] In the present embodiment, after the formation of the seed layer,the seed layer is annealed to align the crystallographic directionthereof in a prescribed direction, thereafter on the seed layer theplating being implemented to form a plating layer.

[0222]FIG. 27 is a flow chart showing a manufacturing process of asemiconductor device involving the present embodiment, FIGS. 28A throughC being vertical sections showing a situation where the semiconductordevice involving the present embodiment is manufactured.

[0223] In the method involving the present embodiment, after a seedlayer 602 is formed on a wafer thereon a barrier metal layer is formed(step 5 (1), FIG. 28A), the wafer W is transferred in the annealing unit(step 5 (2)) to anneal, thereby aligning the crystallographic directionof the seed layer 602 (step 5 (3), FIG. 28B).

[0224] Thereafter, the wafer W is transferred in the plating unit M1(step 5 (4)), a plating layer 603 being further formed on the seed layer602 of which crystallographic direction is aligned (step 5 (5), FIG.28C).

[0225] At that time, in the seed layer 602, as shown in FIG. 28B, due tothe annealing, the crystallographic direction thereof is aligned, thatis, directed in a prescribed direction.

[0226] Accordingly, the plating layer 603 newly formed in the step ofplating is formed so that the crystallographic direction thereof isaligned with that of the seed layer 602.

[0227] The plating layer may be further annealed. In that case, there isobtained an effect that the crystallographic direction is aligned withmore ease.

What is claimed is:
 1. A liquid treatment system, comprising: a firstliquid treatment unit for implementing a first liquid treatment with afirst treatment solution containing metal ion on a substrate; a secondliquid treatment unit for implementing a second liquid treatment on thesubstrate thereon the first liquid treatment is implemented; and a firsttransfer unit for transferring the substrate in a vertical direction;wherein the first and second liquid treatment units are disposed inmulti-tiers in a vertical direction surrounding the first transfer unit.2. The liquid treatment system as set forth in claim 1 : wherein thefirst liquid treatment unit implements the first liquid treatment on afirst surface of the substrate and the second liquid treatments unitimplements the second liquid treatment at least on a second surface ofthe substrate.
 3. The liquid treatment system as set forth in claim 2 :wherein the first transfer means has a function for turning upside downfront and back surfaces of the substrate.
 4. The liquid treatment systemas set forth in claim 1 , further comprising: a first gas feed means forfeeding a cleansed gas in the liquid treatment system; wherein thesecond liquid treatment unit is disposed on an upstream side of the flowof cleansed gas than the first liquid treatment unit.
 5. The liquidtreatment system as set forth in claim 1 , further comprising: a secondtransfer unit for transferring the substrate out of the second liquidtreatment unit.
 6. The liquid treatment system as set forth in claim 1 :wherein the second liquid treatment unit is disposed above the firstliquid treatment unit.
 7. The liquid treatment system as set forth inclaim 1 , further comprising: a third liquid treatment unit forimplementing a third liquid treatment on the substrate, before or afterimplementing the first liquid treatment on the substrate at the firstliquid treatment unit.
 8. The liquid treatment system as set forth inclaim 1 , further comprising: a heating unit for heating the substratethereon the first liquid treatment is implemented.
 9. The liquidtreatment system as set forth in claim 1 , further comprising: atemperature control means for controlling a temperature in the liquidtreatment system.
 10. The liquid treatment system as set forth in claim1 : wherein the first and second liquid treatment units are independentfrom each other and detachable from the liquid treatment system,respectively.
 11. The liquid treatment system as set forth in claim 1 :wherein the first liquid treatment unit has a housing capable ofmaintaining an interior atmosphere thereof approximately airtight. 12.The liquid treatment system as set forth in claim 11 : wherein the firstliquid treatment unit further comprises a second gas feed means forfeeding a cleansed gas in the housing.
 13. The liquid treatment systemas set forth in claim 11 : wherein the first liquid treatment unitfurther comprises an exhaust means for lowering a pressure of thehousing interior than that of the housing exterior.
 14. The liquidtreatment system as set forth in claim 11 : wherein the first liquidtreatment unit further comprises a temperature control means forcontrolling a temperature in the housing.
 15. A liquid treatment method,comprising: a first liquid treatment step for implementing a firstliquid treatment on a substrate by means of a first liquid treatmentunit accommodating a first treatment solution containing a metal ion; acleaning step for water cleaning in the first liquid treatment unit thesubstrate thereon the first liquid treatment is implemented in the firstliquid treatment step; a transfer step for transferring the substratethat is cleansed in the cleaning step, together with adsorbed moisture,by means of a transfer unit, to a second liquid treatment unit; and asecond liquid treatment step for implementing a second liquid treatment,by means of the second liquid treatment unit, on the substratetransferred in the transfer step.
 16. A liquid treatment method,comprising: a first liquid treatment step for implementing a firstliquid treatment on a first surface of a substrate by means of a firstliquid treatment unit accommodating a first treatment solutioncontaining a metal ion; a reversal step for turning, during transfer toa second liquid treatment unit due to a transfer unit, upside down frontand back surfaces of the substrate on which first surface the firstliquid treatment is implemented in the first liquid treatment step; anda second liquid treatment step for implementing, by means of a secondliquid treatment unit, a second liquid treatment on at least a secondsurface of the substrate that is turned upside down in the reversalstep.